What hidden property that now represent the lexical environment carry over any time you return a function from a function (closure)?.

I am little confuse with closure here

“What are closures in JavaScript? How do they function?
Closures allow inner functions to access outer function’s variables even after outer function execution.
Example: function outer() { let x = 10; return function inner() { console.log(x); } } const innerFunc = outer(); innerFunc(); // Output: 10”